Essays on Life 



sea and perish ; that the beetles in Madeira, as 

 observed by Mr. Wollaston, lie much concealed 

 until the wind lulls and the sun shines ; that 

 the proportion of wingless beetles is larger on 

 the exposed Desertas than in Madeira itself; 

 and especially the extraordinary fact, so strongly 

 insisted on by Mr. AVollaston, that certain large 

 groups of beetles, elsewhere excessively nume- 

 rous, which absolutely require the use of their 

 wings are here almost entirely absent ; these 

 several considerations make me believe that 

 the wingless condition of so many Madeira 

 beetles is mainly due to the action of natural 

 selection, combined probably with disuse [italics 

 mine]. For during many successive genera- 

 tions each individual beetle which flew least, 

 either from its wings having been ever so 

 little less perfectly developed or from indo- 

 lent habit, will have had the best chance of 

 surviving, from not being blown out to sea ; 

 and, on the other hand, those beetles which 

 most readily took to flight would oftenest 

 have been blown to sea, and thus de- 

 stroyed." * 



1 " Origin of Species," sixth edition, 1888, vol. i. p. 168. 



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